From: Edmund H White <edmund.h.white@intel.com>
Date: Mon, 12 May 2014 09:59:19 +0000 (+0200)
Subject: Nested VMX: load current_vmcs only when it exists
X-Git-Tag: 4.5.0-rc1~880
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=99c03bc6a1f8c6722926d2db781ece045f9d09ae;p=xen.git

Nested VMX: load current_vmcs only when it exists

There may not have valid vmcs on current CPU. So only load it when it exists.

This original fixing is from Edmud <edmund.h.white@intel.com>.

Signed-off-by: Edmund H White <edmund.h.white@intel.com>
Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/arch/x86/hvm/vmx/vmcs.c b/xen/arch/x86/hvm/vmx/vmcs.c
index cc84ca276c..7564895892 100644
--- a/xen/arch/x86/hvm/vmx/vmcs.c
+++ b/xen/arch/x86/hvm/vmx/vmcs.c
@@ -824,8 +824,12 @@ void virtual_vmcs_enter(void *vvmcs)
 
 void virtual_vmcs_exit(void *vvmcs)
 {
+    struct vmcs_struct *cur = this_cpu(current_vmcs);
+
     __vmpclear(pfn_to_paddr(domain_page_map_to_mfn(vvmcs)));
-    __vmptrld(virt_to_maddr(this_cpu(current_vmcs)));
+    if ( cur )
+        __vmptrld(virt_to_maddr(cur));
+
 }
 
 u64 virtual_vmcs_vmread(void *vvmcs, u32 vmcs_encoding)